Commutator for dynamo-electrjc machines



(No Model.) 2 Sheets-Sheet 1.

C. E. PIPER.

CCMMUTATOR FOR DYNAMO ELECTRIC MACHINES. No. 328,859. H Patented 0012.20, 1885.

(No Model.)

. 2 Sheets-Sheet 2. C. E. PIPER.

GOMMUTATOR FOR DYNAMO ELECTRIC MAGHINBS.

No. 328,859. Patented Oct. 20, 1885.

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UNITED STATES PATENT OFFICE.

CHARLES E. PIPER, OF MOLINE, ILLINOIS.

COMMUTATOR FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No.328,859, dated October 20, 1885,

Application filed May 6, 1884. Serial No. 130,590. (No model.)

To all whom it may concern..-

Be it known that I, CHARLES E. PIPER, of Moline, in the county of Rock Island and State of Illinois, have invented certain new and useful Improvements in Oommutators for Dynamo-Electric, Electro-Magnetic, and other Similar Machines, of which the following is a description, reference being had to the accompanying drawings.

The object of my invention is to provide a commutator for dynamo-electric, electromagnetic, and other kindred machines which may be connected with the armatureooils for either a high or low tension current, and by means of which the current generated in or conveyed to the armature-coils shall pass to and from the brushes without any break in the circuit, thereby preventing reverse induced currents.

To this end it consists in a cylinder with the metallic surfaces insulated from each other transversely, all the metallic sections on each side of the transverse division being electrically connected with all the other sections on the same side and with the armature-coils, while the different metallic sections in each transverse division are separated from each other upon the surface by sections of hard rubber or other insulating material,f0r the purpose and in the manner hereinafter described, and definitely pointed out in the claims.

My invention in the preferable form of construction is illustrated in the drawings, in which Figure 1 is a side view. Fig. 2 is a vertical cross-section. Fig. 3 is an end view, and Fig. 4 is an end view of a modification of my improved commutator. Fig. 5 is a front view of another modification, and Figs.6 and 7 are views of the upper and lower ends, respectively, of the commutator represented by Fig. 5.

The commutators represented by Figs. 4, 5, 6, and 7 are designed for use upon a machine having six armature-coils in the series, the first three figures illustrating a commutator for use upon a machine having four armaturecoils in the series. The number of transverse divisions of the commutator and the number of metallic sections in each transverse division depends, of course, upon the number of armature-coils, the manner in which they are connected, and upon the arrangement of the fieldmagnets.

A represents a hollow cylinder or thimble, made of hard rubber or other insulating material, which fits rigidly upon the revolving shaft which bears the armature.

B represents a hollow metal cylinder enlarged at one end.

0 represents a hollow cylinder of hard rubber or other insulating material, and has one end enlarged to form the transverse flange c.

D represents a hollow metal cylinder of the same external diameter as thelarger end of the cylinder B. The exterior circumferences of the cylinder D and the larger end of B are divided into as many equal parts as there are armature-coils. The alternate divisions on each are cut away sufficient to allow strips of insulating material (I, d, and b to be dovetailed or otherwise fastened into the depressions thus formed.

The various parts,constructed as above desoribed,are put together in the manner shown in Fig. 2. Over the insulating-thimble A is fitted the cylinder B. Over the smaller end of B fits the insulating-cylinder O, and over that the cylinder D, the flange c separating the two metallic cylinders B and D. These two cylinders B and D are so arranged that the lines dividing the metal and rubber surfaces in the one shall be continuous with the lines dividing the same two parts in the other, and so that the metal surfaces in each shall be opposite the insulated surfaces of the other, as is clearly shown in Fig. 1. All the metal surfaces of each transverse division are electrically connected, being parts of the same metal cylinder, and they are connected with the armaturecoils represented by H by the wires 3 and 4.

The brushes F F are metal strips which touch the surface of both transverse divisions of the commutator in a line parallel to the line dividing the metal and insulating surfaces of each, the two brushes being held in position by any appropriate brush-holder, and being connected by the wires 1 and 2 to the lamp or battery G, according as the machine is used as a generator or a motor.

It is evident that when the brush F touches the metal surface of cylinderB and the current passes into the armature-coils H by wire 4. it is touching the insulating-surface of the cylinder D, and no current passes into said cylin- I I I s r,

der from the said brush. The brush F is at the same time in contact with the insulating surface of B and with the metallic surface of D, and receives from D the current from the armature coils. The position of the two brushes upon the surface of the commutator must be such that when in the revolution of the commutator the brush F leaves its electrical connection with the division B and becomes electrically connected with the division D the brush F leaves its electrical connection with the division D and becomes similarly connected with the division B. In the form in Fig. 2 this distance between the lines of contact of the two brushes upon the surface of the commutator is just one-fourth of the circumference. In the form shown in Fig. 4 it is one-sixth of the circumference. By this construction no break is made in the circuit, and consequently no reverse currents are induced, and the wearing away of the commutator by sparking is greatly reduced, as very little sparking occurs. These results may be accomplished if the metallic surfaces in each transverse division are not parts of the same metal cylinder, as shown in Figs. 5, 6, and 7.

Pieces of metal E E,of the proper size, may be set into the surface of a cylinder, A, of rubber or other insulating material, and all the metallic surfaces on each side of the transverse division connected by wires 6 e e e at any time before the connection is made with the armaturecoils.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a commutator in the form ofa cylin der, the metallic surfaces of which are insulated transversely, the combination of the metal cylinder having the enlarged portion forming one of the surfaces and provided with the insulated portions therein, the insulating-sleeve mounted on the smaller end of said cylinder, and a metallic sleeve mounted on said insulating-sleeve and having the sections of insulating material inserted therein, substantially as described.

2. In a commutator, the combination of the insulating core or sleeve, the metal cylinder mounted on said sleeve and having an enlarged end and the insulated strips therein, a sleeve of insulating material fitting over the smaller end of said cylinder,and having a ring or collar extending out flush with the surface of the larger end of the metal cylinder, and a smaller metallic sleeve or cylinder fitted over said insulatingcylinder and provided with the insulating-strips, substantially as described.

3. The combination, with the metal cylinder having the enlarged end, of the sleeve of insulating material fitting over the smaller end of the metal cylinder and having the collar eX- tending out flush with the larger end of the same, the smaller metal cylinder fitting over the insulating-sleeve, and the pieces of insulating material inserted in the surface of the metal cylinders, substantially as described.

CHARLES E. PIPER.

Witnesses:

E. L. THURSTON, F. W. BRAINERD. 

